1. Field of the Invention
The present invention is directed to a commutator for commutator motors having a carrier body with a plurality of electrically conductive segments arranged on the outer circumference of the carrier body.
2. Description of the Prior Art
In commutator motors, commutators of this kind are mounted on the armature shaft of the commutator motor. Contact segments arranged at the commutator are electrically connected to armature windings at the armature shaft.
Commonly used commutators are made of duroplastics with inserted copper segments and are pressed onto armature shafts.
DE 38 32 106 A1 discloses a commutator in which the carrier element comprises a glass fiber-reinforced phenolic resin with mica particles embedded therein.
A primary disadvantage of the commutator of this kind, which is based on a plastic, is that the segments must be embedded over a relatively large space in order to enable sufficient holding forces at high rotating speeds. Due to the resulting larger outer diameters, friction increases at the carbons and wear therefore increases. If the commutator is heated to more than about 160° C. due to overloading of the motor, an irreversible deformation of the commutator can occur. This results in worsened commutation making it necessary to repair or replace the commutator. Another disadvantage consists in the aging of the plastic by ozone which is formed in the electric arc between the carbon and commutator during operation of the commutator motor. Over longer periods of time, electrical safety margins can be reduced to critical values in this way.
JP 11 187 621 discloses a commutator with a ceramic carrier body in which the electrically conductive surface segments are formed by a notched copper layer.
This is disadvantageous due to the low dielectric strength of the ceramic and higher production costs.
Therefore, it is the object of the present invention to develop a commutator of the type mentioned above which avoids the disadvantages mentioned above and can be manufactured in a favorable manner.